1. The Field of the Invention
The present invention relates generally to electrical connectors. More specifically, exemplary embodiments of the present invention relate to electrical connectors for use with optical subassemblies and printed circuit boards.
2. Related Technology
Fiber optic technology is increasingly employed as a method by which information can be reliably transmitted via a communications network. Networks employing fiber optic technology are known as optical communications networks, and are marked by high bandwidth and reliable, high-speed data transmission.
Optical communications networks employ optical transceivers in transmitting information via the network from a transmission node to a reception node. Generally, such optical transceivers implement both data signal transmission and reception capabilities, such that a transmitter portion of a transceiver converts an incoming electrical data signal into an optical data signal, while a receiver portion of the transceiver converts an incoming optical data signal into an electrical data signal.
More particularly, an optical transceiver at the transmission node receives an electrical data signal from a network device, such as a computer, and converts the electrical data signal to a modulated optical data signal using an optical transmitter such as a laser. The optical data signal can then be transmitted in a fiber optic cable via the optical communications network to a reception node of the network. Upon receipt by the reception node, the optical data signal is fed to another optical transceiver that uses a photodetector, such as a photodiode, to convert the received optical data signal back into an electrical data signal. The electrical data signal is then forwarded to a host device, such as a computer, for processing.
Generally, multiple components are designed to accomplish different aspects of these functions. For example, an optical transceiver can include one or more optical subassemblies (“OSA”) such as a transmit optical subassembly (“TOSA”), and a receive optical subassembly (“ROSA”). Typically, each OSA is created as a separate physical entity, such as a hermetically sealed cylinder that includes one or more optical sending or receiving components, as well as electrical circuitry for handling and converting the optical signals. Within the optical transceiver, each OSA generally includes electrical connections to various additional components such as a transceiver substrate, sometimes embodied in the form of a printed circuit board (“PCB”).
The transceiver substrate can include multiple other active circuitry components particularly designed to drive or handle electrical signals sent to or returning from one or more of the electrically-attached OSAs. Accordingly, such a transceiver substrate will usually include a number of electrical transmission lines with the one or more OSAs. Such connections may include “send” and “receive” data transmission lines for each OSA, one or more power transmission lines for each OSA, and one or more diagnostic data transmission lines for each OSA. These transmission lines are connected between the transceiver substrate and the OSA using different types of electrical connectors, examples of which include an electrical flex circuit, a direct mounting connection between conductive metallic pins extending from the OSA and solder points on the PCB, and a plug connection that extends from the PCB and mounts into electrical extensions from an OSA.
Each of these methods for electrically connecting the OSA with a transceiver substrate implicates various complications relating to matters such as manufacturing processes, and overall cost associated with the device. These, and other, complications become particularly acute in the context of small form factor components. For example, when an OSA has been mounted within a transceiver housing, the spatial relationship of the optical transmit or receive component, as applicable, of the OSA relative to the transceiver housing 160 must closely conform to various predetermined alignment conditions. However, establishment and maintenance of such a spatial relationship may result in a less than optimal or desirable arrangement of other portions of the OSA relative to the transceiver housing and/or relative to the associated transceiver substrate.
With particular reference to small form factor components, small spatial variations of only thousandths of an inch, or mils, at the optical component end of the OSA can create difficulties with the standardized manufacturing process used to electrically connect the opposing end of the OSA to the PCB. As well, small changes to the spatial relationship of the OSA, such as may result from normal system operations occurring over a period of time, can damage or destroy the electrical connection between the OSA and the PCB. Thus, at least some of the difficulties associated with establishing a secure and reliable electrical connection between an OSA and PCB relate to the strict alignment requirements imposed on the various components that make up the optical transceiver.
Accordingly, what is need are electrical connectors that provide for a reliable and secure electrical connection between components such as an OSA and PCB. Further, such electrical connectors should be able to compensate for any misalignment between the OSA and PCB that may occur during assembly or subsequently, without materially compromising the electrical connection therebetween.